Inline check_compilers

This function is used just once. It also seems all policy and no
mechanism (it raises, it calls the same function to do all the work
twice in a simple way). This makes it seem to be as a good candidate for
inlining.

`environment` and `coredata` are woefully intertwined and while this
change doesn't fix that, but at least it makes it easier to follow.

mesonbuild/environment.py

@@ -1127,14 +1127,6 @@ class Environment:
 
         return comp, cross_comp
 
-    def check_compilers(self, lang: str, comp: Compiler, cross_comp: Compiler):
-        if comp is None:
-            raise EnvironmentException('Tried to use unknown language "%s".' % lang)
-
-        comp.sanity_check(self.get_scratch_dir(), self)
-        if cross_comp:
-            cross_comp.sanity_check(self.get_scratch_dir(), self)
-
     def detect_compilers(self, lang: str, need_cross_compiler: bool):
         (comp, cross_comp) = self.compilers_from_language(lang, need_cross_compiler)
         if comp is not None:

mesonbuild/interpreter.py

@@ -2696,7 +2696,11 @@ external dependencies (including libraries) must go to "dependencies".''')
             else:
                 try:
                     (comp, cross_comp) = self.environment.detect_compilers(lang, need_cross_compiler)
-                    self.environment.check_compilers(lang, comp, cross_comp)
+                    if comp is None:
+                        raise InvalidArguments('Tried to use unknown language "%s".' % lang)
+                    comp.sanity_check(self.environment.get_scratch_dir(), self.environment)
+                    if cross_comp:
+                        cross_comp.sanity_check(self.environment.get_scratch_dir(), self.environment)
                 except Exception:
                     if not required:
                         mlog.log('Compiler for language', mlog.bold(lang), 'not found.')